Hydronic floor heating systems with features

ABSTRACT

A hydronic floor heating system as it relates to an HVAC apparatus, approach and system. Aspects of the present system and approach may include a radiant floor optimization mode, low floor temperature in vacation mode, modifying a 300 Hz, or so, reading principle base on implementation of Pseudo-random jittering of a reading event improving short-term accuracy of the individual readings, and a combination of hardware and software filters for using thermal sensors with extended cable length.

This application is a divisional of U.S. application Ser. No.16/150,053, FILED Oct. 2, 2018 and entitled, “HYDRONIC FLOOR HEATINGSYSTEMES WITH FEATURES,” which claims the benefit of U.S. ProvisionalApplication No. 62/567,159, filed Oct. 2, 2017, entitled “Features ofHydronic Floor Heating Systems”, the full disclosures of which arehereby incorporated by reference.

BACKGROUND

The present disclosure pertains to hydronic floor heating systems andparticularly to energy efficiencies of such systems adaptable to a widerange of circuit configurations.

SUMMARY

The disclosure reveals a hydronic floor heating system as it relates toan HVAC apparatus, approach and system. Aspects of the present systemand approach include a radiant floor optimization mode, low floortemperature in vacation mode, modifying the 300 Hz reading principlebase on implementation of Pseudo-random jittering of a reading eventimproving short-term accuracy of the individual readings, and acombination of hardware and software filters for using thermal sensorswith an extended cable length.

BRIEF DESCRIPTION OF THE DRAWING

The disclosure may be more completely understood in consideration of thefollowing description of various illustrative versions of the disclosurein connection with the accompanying figures.

FIG. 1 is a schematic view of an illustrative HVAC system servicing abuilding or other structure;

FIG. 2 is a schematic view of an illustrative HVAC controller that mayfacilitate access and/or control of the HVAC system of FIG. 1;

FIG. 3 is a schematic view of an illustrative HVAC control system thatmay facilitate access and/or control of the HVAC system of FIG. 1;

FIGS. 4A-4B are schematic views of illustrative screens of an HVACcontroller showing an approach for initiating an HVAC controller toencode settings and/or data on the user interface of the HVACcontroller;

FIGS. 5A-5B are graphical charts of the vacation mode set to OFF/ON inaccordance with the subject disclosure;

FIGS. 6A-6B are schematic views of an illustrative approach of utilizingextended cable in accordance with extended cable length; and

FIGS. 7A-7B are graphical representation of implementing a pseudo randomjittering of a reading event in accordance with the subject disclosure.

DESCRIPTION

The present system and approach may incorporate one or more processors,computers, controllers, user interfaces, wireless and/or wireconnections, and/or the like, in an implementation described and/orshown herein.

This description may provide one or more illustrative and specificexamples or ways of implementing the present system and approach. Theremay be numerous other examples or ways of implementing the system andapproach.

The following description should be read with reference to the drawingswherein like reference numerals indicate like elements. The drawings,which are not necessarily to scale, are not intended to limit the scopeof the disclosure. In some of the figures, elements not believed neededfor an understanding of relationships among illustrated components mayhave been omitted for clarity.

All numbers are herein assumed to be modified by the term “about”,unless the content clearly dictates otherwise. The recitation ofnumerical ranges by endpoints includes all numbers subsumed within thatrange (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” include the plural referents unless thecontent clearly dictates otherwise. As used in this specification andthe appended claims, the term “or” is generally employed in its senseincluding “and/or” unless the content clearly dictates otherwise.

It is noted that references in the specification to “a version”, “someversions”, “other versions”, and so forth, indicate that the versiondescribed may include a particular feature, structure, orcharacteristic, but every version may not necessarily include theparticular feature, structure, or characteristic. Moreover, such phrasesare not necessarily referring to the same version. Further, when aparticular feature, structure, or characteristic is described inconnection with a version, it is contemplated that the feature,structure, or characteristic may be applied to other versions whether ornot explicitly described unless clearly stated to the contrary.

The present disclosure is directed generally at building automationsystems. Building automation systems are systems that control one ormore operations of a building. Building automation systems can includeHVAC systems, security systems, fire suppression systems, energymanagement systems and other systems. While HVAC systems with HVACcontrollers are used as an example below, it should be recognized thatthe concepts disclosed herein may be applied to building automationsystems more generally.

For the purposes of providing an illustrative example, the variousversions of the present disclosure are described in the context of anHVAC system. However, it is generally understood that many of theversions described herein may be utilized in connection with otherbuilding appliances and are not limited to use with an HVAC system.

Low Floor Temperature in a “Vacation” mode may be noted. Hydronic floorheating systems may allow setting a Low Floor Temperature Limit, whichitself may appear difficult to understand, but can significantly affectthermal comfort and energy bills. To satisfy thermal comfort and keepthe energy bills low, another specific Limit value should be set alsofor a vacation mode. Making the parameter configurable and havingseveral of them (one per each schedule period plus a vacation mode) mayconfuse users as well as contractors as they may not necessarilyunderstand its meaning. An incorrect value of the parameter may increaseenergy consumption, and on top of that it may significantly extendinitial installation and create an opportunity for incorrect settings.

This feature may be unique in the hydronic floor heating market. It maykeep the initial configuration very simple and quick. A user/contractormay have to configure only one single Low Floor Temperature limit anddoes not necessarily have to care about its settings and values invacation mode, as it can be ignored to save energy bills. This maysignificantly improve user experience while reducing installation time.

One may implement a vacation mode in a way how a user understands it themost. Only an “away” setpoint may be maintained (either air or floorbased on control mode). The Low floor temperature limit may be ignoredsince there is no need to satisfy comfort recovery to “occupied” periods(wake, return) while no one is home. Some contractors may use the LowFloor temperature limit as freeze protection, which is not necessarilyneeded in this case, because it is a separate feature, so again thelimit is not necessarily needed for the mode.

Radiant floor optimization may be noted. To satisfy thermal comfort andkeep energy bills low, the low floor temperature Limit value shouldchange with temperature schedule. Making the low floor temperature Limitparameter configurable may confuse users as they may not understand itsmeaning. Having contractors to create week schedule for the parametermay difficult to understand and confuse contractors.

This feature appears unique in the hydronic floor heating market. It mayneed only a “Yes/No” answer from a user/contractor compared to forcingthe user/contractor to understand the Low Floor Temperature Limit orforcing contractor to schedule the Low floor temperature limitparameter. This may significantly improve user experience while reducinginstallation time.

An optimization feature may be created, which when enabled, can ignorethe Low floor Temperature Limit during “unoccupied” periods (i.e., Away,Sleep), which can prevent rooms from overheating as well limit use ofheating equipment, which can reduce energy bills. Thermal comfort may besatisfied as users do not touch/walk the floors during the unoccupiedperiods. From a user's perspective there may be an ISU or user menu itemwhich is called “Economy mode” (or a similar name) and provide options“Yes/No”. A “Yes” option may ignore the Low Floor Temperature Limitduring the occupied periods. The “No” option may maintain the Low FloorTemperature Limit when any period is active.

The present approach may have a software component. A stack level suchas a sensor may be a hardware device with some embedded software formeasuring/detecting and transmitting data (e.g., temperature, pressure,motion, and the like). The embedded software may run in a device/unit(e.g., firmware).

A combination of hardware and software filters for using thermal sensorswith extended cable length may be noted. Connecting of externaltemperature sensors to a thermostat may be influenced by various kindsof interferences. A main source of interference may be AC supply lines.Due to a possible transmission of interference from AC lines to sensorcables, the lengths of the cables may be limited. With a use of ahardware filter in combination with a special software measuringalgorithm, the lengths of the cables may be increased up to 100 meters.A current situation is that thermostats do not necessarily use cableslonger than 5 meters or their measurements may be inaccurate.

Many installations of external temperature sensors may be limited bycable length. Current installations often use cables up to 5 meterslong. Longer cables are not necessarily recommended; instead, specialand expensive shielded cables should be used. A benefit of this solutionmay be a use of a sensor with a cheap connection cable and afunctionality that is the same as an expensive shielded cable. Theresult may be higher performance with low cost components. This may havea direct impact on customers, who may get a better product for a lowerbetter price.

The present mechanism may have two parts—hardware (HW) and software(SW). The hardware part may contain a sensor connected to thermostatterminals and a measuring circuit on a thermostat PCB (e.g., a printcircuit board). The measuring circuit may contain a capacitive low passfilter which filters out interference at higher frequencies. Thesoftware part may contain a 300 Hz sampling process that ensures afiltering of 50 Hz and 60 Hz AC line interference. Other frequencies maybe incorporated. The software filtering may also contain pseudo randomjittering, which ensures cancellation of static reading errors whichcould occur in special cases as an interference product of a linevoltage frequency deviation and a reading interval rate. Altogether,this arrangement may be a robust filter. The arrangement may be used incommon installations where an extended cable appears to be needed orwhere high interference can be expected, such as, for example, measuringtemperatures in different rooms, measuring outdoor temperatures, or arouting of sensor cables close to AC lines.

The software component may have a stack level that is a sensorincorporating a hardware device with some embedded software formeasuring/detecting and transmitting data (e.g., temperature, pressure,motion, and/or so on). A software type may involve embedded softwarerunning in a device/unit (e.g., firmware).

Modification of the 300 Hz reading principle based on implementation ofpseudo-random jittering of a reading event improving short-term accuracyof the individual readings may be noted. The room thermostats may read atemperature from an external sensor (thermistor) wired to thethermostat. Because the wires do not necessarily have to be shielded,then the noise at a corresponding A/D converter's input may berelatively strong; and when the sensor's cable is located close a linevoltage distribution, the noise may contain a significant 50 Hz or 60 Hzcomponent. Such specific components may make it possible to attenuate ifa so-called 300 Hz reading principle is used (one reading consists of 30samples captured during 96.7 ms). Other numbers or numerical values maybe used. If the line voltage frequency is shifted from an ideal value,then the individual readings of temperature (consisting of 30 samples)may start to oscillate around the real value. The frequency of theoscillations may equal the line voltage frequency to reading a frequencydifference. Normally, these oscillations may be eliminated by utilizinga moving average or another filtering principle, because a mean of theoscillations may correspond with the real value. An issue may occur whenthe frequency difference is negligible and therefore the oscillationshave a very low frequency (one period per hour, for instance). Theproblem may periodically occur at, for instance, 51.0, 52.0, 53.0 Hz,and so on, if the reading interval is 1 second. This very low frequencyproduct (a so-called beat) may cause a short term remaining readingshift which might be interpreted like a temperature change because thefiltration cannot reject so low frequencies without affecting responsetime of the thermostat to a real temperature change.

If the reading period is still exactly 1/300 Hz but the individualreadings are randomly phase swept with (some readings are earlier, somelater, but on the whole its count is 300 per second), and the amplitudeof the phase jittering range is at least +/−20 ms, then very undesiredvery low frequency products may be broken and the reading error may havenow a pseudo-random character around the real temperature and the longtime remaining reading shifts cannot necessarily occur.

The reading interval may be one or more second (typically, 20 second)period and the individual readings may have to be spread around thenominal times. The spread interval should be at least +/− 1/50 Hz=+/−20ms, and the samples should be spread randomly in the interval. Apseudo-random function may be used for this purpose. The 300 Hzfiltration principle with readings of the pseudorandom jitter, may beadvisably combined with suitable hardware pre-filtration whichattenuates noise at higher frequencies. The approach and system may havea software component. There may be a stack level sensor that can be ahardware device with some embedded software measuring, detecting andtransmitting data (e.g., temperature, pressure, motion). The softwaretype may be embedded, such as software that runs in a device/unit (e.g.,firmware).

FIG. 1 is a schematic view of a building 2 having an illustrativeheating, ventilation, and air conditioning (HVAC) system 4. While FIG. 1shows a typical forced air type HVAC system, other types of HVAC systemsare contemplated including, but not limited to, boiler systems, radiantheating systems, electric heating systems, cooling systems, heat pumpsystems, and/or any other suitable type of HVAC system, as desired. Theillustrative HVAC system 4 of FIG. 1 may include one or more HVACcomponents 6, a system of ductwork and air vents including a supply airduct 10 and a return air duct 14, and one or more HVAC controllers 18.The one or more HVAC components 6 may include, but are not limited to, afurnace, a heat pump, an electric heat pump, a geothermal heat pump, anelectric heating unit, an air conditioning unit, a humidifier, adehumidifier, an air exchanger, an air cleaner, a damper, a valve,and/or the like.

It is contemplated that the HVAC controller or controllers 18 may beconfigured to control the comfort level in the building or structure byactivating and deactivating the HVAC component or controllers 6 in acontrolled manner. The HVAC controller or controllers 18 may beconfigured to control the HVAC component or components 6 via a wired orwireless communication link 20. In some cases, the HVAC controller orcontrollers 18 may be a thermostat, such as, for example, a wallmountable thermostat, but this is not necessarily needed in allversions. Such a thermostat may include (e.g., within the thermostathousing 200, FIG. 6B) or have access to one or more temperature sensorsfor sensing ambient temperature at or near the thermostat. In someinstances, the HVAC controller or controllers 18 may be a zonecontroller, or may include multiple zone controllers each monitoringand/or controlling the comfort level within a particular zone in thebuilding or other structure.

In the illustrative HVAC system 4 shown in FIG. 1, the HVAC component orcomponents 6 may provide heated air (and/or cooled air) via the ductworkthroughout the building 2. As illustrated, the HVAC component orcomponents 6 may be in fluid communication with every room and/or zonein the building 2 via the ductwork 10 and 14, but this is notnecessarily needed. In operation, when a heat call signal is provided bythe HVAC controller or controllers 18, an HVAC component 6 (e.g., forcedwarm air furnace) may be activated to supply heated air to one or morerooms and/or zones within the building 2 via supply air ducts 10. Theheated air may be forced through supply air duct 10 by a blower or fan22. In this example, the cooler air from each zone may be returned tothe HVAC component 6 (e.g., forced warm air furnace) for heating viareturn air ducts 14. Similarly, when a cool call signal is provided bythe HVAC controller or controllers 18, an HVAC component 6 (e.g., airconditioning unit) may be activated to supply cooled air to one or morerooms and/or zones within the building or other structure via supply airducts 10. The cooled air may be forced through supply air duct 10 by theblower or fan 22. In this example, the warmer air from each zone may bereturned to the HVAC component 6 (e.g., air conditioning unit) forcooling via return air ducts 14. In some cases, the HVAC system 4 mayinclude an internet gateway or other device 23 that may allow one ormore of the HVAC components, as described herein, to communicate over awide area network (WAN) such as, for example, the Internet.

In some cases, the system of vents or ductwork 10 and/or 14 can includeone or more dampers 24 to regulate the flow of air, but this is notnecessarily needed. For example, one or more dampers 24 may be coupledto one or more HVAC controllers 18, and can be coordinated with theoperation of one or more HVAC components 6. The one or more HVACcontrollers 18 may actuate dampers 24 to an open position, a closedposition, and/or a partially open position to modulate the flow of airfrom the one or more HVAC components 6 to an appropriate room and/orzone in the building or other structure. The dampers 24 may beparticularly useful in zoned HVAC systems, and may be used to controlwhich zone or zones receive conditioned air from the HVAC component orcomponents 6.

In many instances, one or more air filters 30 may be used to remove dustand other pollutants from the air inside the building 2. In theillustrative example shown in FIG. 1, the air filter or filters 30 areinstalled in the return air duct 14, and may filter the air prior to theair entering the HVAC component 6, but it is contemplated that any othersuitable location for the air filter or filters 30 may be used. Thepresence of the air filter or filters 30 may not only improve the indoorair quality, but may also protect the HVAC components 6 from dust andother particulate matter that would otherwise be permitted to enter theHVAC component.

In some cases, and as shown in FIG. 1, the illustrative HVAC system 4may include an equipment interface module (EIM) 34. When provided, theequipment interface module 34 may, in addition to controlling the HVACcomponents 6 under the direction of the thermostat, be configured tomeasure or detect a change in a given parameter between the return airside and the discharge air side of the HVAC system 4. For example, theequipment interface module 34 may measure a difference in temperature,flow rate, pressure, or a combination of any one of these parametersbetween the return air side and the discharge air side of the HVACsystem 4. In some cases, the equipment interface module 34 may beadapted to measure the difference or change in temperature (delta T)between a return air side and discharge air side of the HVAC system 4for the heating and/or cooling mode. The delta T for the heating andcooling modes may be calculated by subtracting the return airtemperature from the discharge air temperature (e.g., delta T=dischargeair temperature−return air temperature).

In some cases, the equipment interface module 34 may include a firsttemperature sensor 38 a located in the return (incoming) air duct 14,and a second temperature sensor 38 b located in the discharge (outgoingor supply) air duct 10. Alternatively, or in addition, the equipmentinterface module 34 may include a differential pressure sensor includinga first pressure tap 39 a located in the return (incoming) air duct 14,and a second pressure tap 39 b located downstream of the air filter 30to measure a change in a parameter related to the amount of flowrestriction through the air filter 30. In some cases, the equipmentinterface module 34, when provided, may include at least one flow sensorthat is capable of providing a measure that is related to the amount ofair flow restriction through the air filter 30. In some cases, theequipment interface module 34 may include an air filter monitor. Theseare just some examples.

When provided, the equipment interface module 34 may be configured tocommunicate with the HVAC controller 18 via, for example, a wired orwireless communication link 42. In other cases, the equipment interfacemodule 34 may be incorporated or combined with the HVAC controller 18.In some instances, the equipment interface module 34 may communicate,relay or otherwise transmit data regarding the selected parameter (e.g.,temperature, pressure, flow rate, and so forth) to the HVAC controller18. In some cases, the HVAC controller 18 may use the data from theequipment interface module 34 to evaluate the system's operation and/orperformance. For example, the HVAC controller 18 may compare datarelated to the difference in temperature (delta T) between the returnair side and the discharge air side of the HVAC system 4 to a previouslydetermined delta T limit stored in the HVAC controller 18 to determine acurrent operating performance of the HVAC system 4.

Radiant Floor Optimization and Vacation Mode may be noted. HVACcontroller 18 may display a home screen 120 on the display 86 (FIG. 4A),which shows the time 122, current temperature 124, a fan status 126, anHVAC system status 128, a back button 130 represented by “−”, a Modebutton 132, a Menu button 134, a Fan button 136, and a forward button138 represented by “+”. From the home screen 120, a user may begin byselecting the Menu button 134 at the same time as the forward button 138in order enter an installer setup screen 140 (see FIG. 4B). In somecases, needing a selection of two or more buttons simultaneously mayhelp prevent a homeowner from inadvertently entering the installer setupscreen.

Mode button 132 allows the user to select system mode of “Heat” or“Off”. Menu button 134 may be pressed to display options. This istypically where a user starts to set a program schedule. Further, thedisplay 86 will wake up by pressing any of the five buttons. The display86 screen may be lit for up to 45 seconds, or other duration, after theuser completes changes. Optionally, the user may set the thermostat 18to keep the display 86 light always on.

A user may be an installer, an HVAC professional, and/or serviceprovider.

The programmable thermostat 18 may be powered by a C wire, alkalinebattery or other power means. Batteries are optional and may providebackup power but the thermostat 18 is wired to run on AC power.

Similarly, the display 86 may have a plurality of different screens.Each screen may have areas that display various information such asicons, graphics, numbers, and letters as needed to accomplish operationin accordance with the present system and approach. The display 86button may also be a touchscreen to receive user input.

The display 86 may further include system status 18 information toindicate when the thermostat is in “Heat On” or “Recovery” mode.Schedule information 14 may inform the user when the system is followingtime based schedule by displaying the phrase “Following Schedule” at 128(FIG. 4A). A digital clock may be shown to display the actual time at122.

Schedules can be in the thermostat 18, in home controlling lights orsuch, or in the cloud controlling multiple devices in multiplelocations.

As discussed above, the HVAC controller 18 may communicate with the oneor more HVAC components 6 of the HVAC system 4 via a wired or wirelesslink 20. The HVAC controller 18 in FIG. 2 may be a connected HVACcontroller 18 that is connectable to a network, or may be annon-connected HVAC controller 18 that may not be capable of connectingto a network (other than the wired or wireless link 20 to one or moreHVAC components 6 of the HVAC system 4).

It is envisioned that the floor temperature may be measured from heatingelements 40 creating a grid under the entire floor area. The heatingelements 40 may be electric cables, heating panels, hot water tubing andthe like as is well known in the art. The floor temperature sensor 32may also be embedded in the floor area. The heating elements 40 andfloor temperature sensor 32 may be in communication with a controller 18within the thermostat. The controller 18 may also be in communicationwith the room ambient temperature sensor 43 and external sensor 12. Thecontroller 18 also is able to communicate with various networks such asa local network and the Internet via wired or wireless devices.

Referring to FIG. 3, In many cases, the HVAC controller 18 may includean input/output block (I/O block) 100 for providing one or more controlsignals to the HVAC system 4. For example, the I/O block 100 maycommunicate with one or more HVAC components 6 of the HVAC system 4. TheHVAC controller 18 may have any number of wire terminals for receivingcontrol wires for one or more HVAC components 6 of the HVAC system 4.Different HVAC systems 4 may have different HVAC components and/or typeof HVAC components 6, which may result in different wiringconfigurations. In some cases, the I/O block 100 may communicate withanother controller, which is in communication with one or more HVACcomponents 6 of the HVAC system 4, such as a zone control panel in azoned HVAC system, equipment interface module (EIM) (e.g., EIM 34 shownin FIG. 1) or any other suitable building control device.

The HVAC controller 18 may also include one or more sensors 102 such asfor example, a temperature sensor, a humidity sensor, an occupancysensor, a proximity sensor, and/or the like. In some cases, the sensoror sensors 102 of the HVAC controller 18 may include an internaltemperature sensor, but this is not necessarily needed. Alternatively,or in addition, the HVAC controller 18 may communicate with one or moreremote temperature sensors, humidity sensors, occupancy sensors, and/orother sensors located throughout the building or structure.Additionally, the HVAC controller may communicate with a temperaturesensor, humidity sensor, and/or other sensors located outside of thebuilding or structure for sensing an outdoor temperature and/or humidityif desired.

The user interface 108 (FIG. 4A), when provided, may be any suitableuser interface that permits the HVAC controller 18 to display and/orsolicit information, as well as accept one or more user interactionswith the HVAC controller 18. For example, the user interface 108 maypermit a user to locally enter data such as temperature set points,humidity set points, fan set points, starting times, ending times,schedule times, diagnostic limits, configuration settings, responses toalerts, and the like. In one version, the user interface 108 may be aphysical user interface that is accessible at the HVAC controller 18,and may include a display 86 and/or a distinct keypad. The display 86may be any suitable display. In some instances, a display may include ormay be a liquid crystal display (LCD), and in some cases an e-inkdisplay, fixed segment display, or a dot matrix LCD display. In oneexample, where the display 86 may be a fixed segment display, the fixedsegment display may include a plurality of fixed segments at fixedlocations that form characters, icons, and/or menu items to interactwith a user of the HVAC controller 18 and/or provide information to auser of the HVAC controller 18. Alternatively or in addition, the userinterface 108 may be a touch screen LCD panel or other touch sensitivescreen that functions as both display and keypad. The touch screen LCDpanel may be adapted to solicit values for a number of operatingparameters and/or to receive such values, but this is not necessarilyneeded. In still other cases, the user interface 108 may be a dynamicgraphical user interface.

A hydronic floor heating system may incorporate one or more thermostats18. Each thermostat 18 may include a controller 18 that integrates anexternal temperature sensor measuring circuit 37 (FIG. 2) having anexternal temperature sensor 12, with a floor temperature sensor 32 and aroom ambient temperature sensor 43 provided for each thermostat 18, andwhose temperature readings are fed to a processor 96 to control thefloor temperature of an underfloor heating system in one or more roomsor areas of a building. The processor 96 can include, withoutlimitation, a central processing unit, an arithmetic logic unit, anapplication specific integrated circuit, a task engine, Wi-Fi module,and/or any combinations, arrangements, or multiples thereof notexplicitly shown. The processor 96 may also be in communication with amemory 98, such as random access memory (RAM), rewritable flash memory,read only memory (ROM). The memory 98 may include software to performthe functions of the present system and approach and may be acombination of integral and external components.

The external temperature sensor measuring circuit 37 may incorporatecomponents for receiving, processing, displaying and/or transmittingdigital and/or analog data. The external temperature sensor measuringcircuit 37 may also be included within the controller. Various othercircuity may also be included as needed for proper operation. Thecontroller 35 may include A/D conversion circuitry, an integral displaydriver, various connection ports and the like.

Each thermostat 18 may have dual sensor ability to control both the roomtemperature and the floor temperature. Each thermostat 18 may alsooperate with room ambient sensor 43 only or floor sensor 32 only. Thefloor temperature is monitored to ensure that the floor temperature doesnot exceed regulatory limits. Should the floor temperature reach themaximum regulatory limits, heating of the floor will cease until thetemperature has lowered again.

The external air sensor 12 signals the outside temperature to theindividual room thermostat or thermostats 18. The maximum floortemperature of each room may be altered depending on the externaltemperature. The reading from the external air temperature sensor 12 maybe processed and a digital or analogue signal will convey the outsidetemperature information to any number of individual room thermostats.

The programmable thermostat 18 can be set to operate in one of 3different control modes. These settings may determine which temperatureis measured, controlled and displayed on the thermostat home screendisplay 86.

Referring to FIGS. 4A-4B, a program schedule may store an instruction toallow the user to program operation of the controller. In the economymode of operation, the floor heating system does not maintain a lowfloor temperature when the room is unoccupied, and upon ending theeconomy mode a low floor temperature may be maintained in the floorheating system irrespective of the occupancy state of the room. Thedisplay 86 of the hydronic floor heating system may provide a Yes/Nooption to the user to select the economy mode.

“A” mode may describes air temperature only. When selecting “A” mode, itmay control and display the ambient or room air temperature only. “F”mode may control the floor temperature only. When selecting “F” mode, itmay control and display the floor temperature only using an externalfloor temperature sensor 12. This control mode typically may be used inareas such as bathrooms where floor temperature could be scheduled to bewarm only during occupied morning and evening periods. Actual floortemperature may be indicated by “FLR” text at the indoor temperaturesetpoint 21 (FIG. 4A) above the actual floor temperature value 124.Likewise, actual ambient air temperature could also be displayed in thedisplay 86.

“AF” mode describes both Air and Floor temperatures. AF mode may controland display the ambient air temperatures as well as maintain the floortemperature within desired floor temperature limits using an externalfloor temperature sensor 12. Setting the minimum and maximum floortemperature limits may be done by a user as a way of enhancing thecomfort and protecting the floor covering at the same time. In “AF”mode, minimum floor temperature limit may override the air temperature.Actual floor temperature may also be displayed on the thermostat bypressing MENU/TEMP.

If the thermostat 18 is configured to operate in “AF” mode and theprogram schedule is followed, a user may disable the preset minimumfloor temperature limits. Disabling the minimum floor temperature limitcan reduce energy bills during times when comfort is not necessarilyneeded (Away and Sleep periods). The floor covering and system remainsprotected as the thermostat 18 keeps controlling maximum floortemperature limit and minimum freeze protection temperature all thetime.

Recommended maximum floor temperature may be 90° F. (32° C.) for mostfloor covering types. An example maximum floor temperature for woodfloor may be 85° F. (29.5° C.). Freeze protection temperature forgarages and basements may be set between 41-45° F. (5-7.2° C.).

An example installer setup screen 140 is depicted in FIG. 4B, whichshows a menu item indicator 142 that, in this case depicts Low FloorMode Setup 142, a back button 130, a forward button 138, a select button144, and a home button 146. One may scroll to menu items other than“ISU” by selecting the forward button 138. Once a desired menu item isdisplayed (e.g., the installer Set Up (ISU) in this case) at the menuitem indicator 142, the user may select the designed menu by selectingthe forward button 138 simultaneously with the select button 144, or insome cases, just the select button 144.

Program schedule may also be programmable to allow the user to selectYes or No when presented with the option of setting the lowertemperature limit.

Further, Economy (ECO) mode may also be utilized only if thermostat 18is configured for AF control mode and is disabled (OFF) by default. Oncein ECO mode, a user may be provided a Yes/No option to ignore low floortemperature limits set during the period. When the user selects Yes, thesystem may ignore low floor temperature limit during this period. If theuser selects No, the system may maintain the low floor limit previouslyset. With adaptive intelligent recovery (AIR), the thermostat 18 maylearn how long it takes the system to reach the temperature that onewants. It may then turn on the heating system earlier to make sure theuser is comfortable at the time expected. AIR is a comfort setting.

Heating or cooling equipment may turn on earlier, ensuring the indoortemperature will match the setpoint at the schedule time.

That is, the ambient room temperature sensor 43 may predict a futureoccupancy level based on measured occupancy data and store this data inthe memory 98 as a user's choice. The processor 96 may contain ananalysis and prediction software program for analyzing and interpretingthe data inputs, such as to develop a measure of building performance.In addition, the processor 96 may contain software program for formingpredictive models, such as predicting future occupancy of the room orbuilding and/or predicting indoor conditions. This data may then be usedto operate the thermostat 18.

Alternatively, if the room will be unoccupied for a set amount of time,temperature (for example 75° F.) may be set as a control targettemperature and the sensor circuit 37 will perform a control whichmaintains this temperature. After selecting the menu button 134, theuser will be able to select TEMP to let the low floor temperature. Oncethe user presses buttons 130, 138 to the desired low temperature, thescreen may display “Yes” or “No” repeatedly for a set period of timeuntil the user presses the select button (FIG. 4B) to denote acceptanceor disapproval, respectively.

A user may also configure one single low floor temperature limit invacation mode to affect thermal comfort and lower energy bills. Vacationmode overrides the current program schedule for a longer period of time.One may use this feature when being away for an extended period of time.Once a user presses the button Menu 17 on the thermostat 18,temperature/navigation buttons 20 can be used to select button “VACA”.The days number may start to blink and the user will continue to set thenumber of days for the new temperature setpoint to override the programschedule. Once a user presses the select button, the temperaturesetpoint starts blinking. Pressing temperature/navigation buttons 20further allows the user to adjust the temperature setpoint for thenumber of selected days. Pressing select button once more, furtheractivates the vacation schedule and restores to the thermostat homescreen.

The activation vacation schedule is indicated via VACA above the actualtemperature 124 on the display 86. After the vacation period ends, thethermostat 18 may follow the regular program schedule.

FIG. 5A, illustrates a regular day schedule when ECO is OFF and thelower floor temperature limit is set to 75° F. As shown, the temperatureremains at 75° F. during Sleep, Wake Away and Return modes. FIG. 5B,illustrates the effect of a regular day schedule including vacationmode. The effect of ECO being ON as compared to the actual low floortemperature limit value of 75° F. for each plot. The low floortemperature limit remains at 75° F. during Wake and Return modes.

Hardware and software filters with extended cable length may be noted.Referring to FIGS. 6A-6B, in another version, the housing 200 of theHVAC controller 18 may be configured to house the display 86, theprinted circuit board (PCB) 60, measuring circuit 70, thermostatterminals, and the temperature sensor 102. Specifically, whilst atemperature sensor 102 attached to a printed circuit board 60 isdimensionally very stable it is in close proximity to the circuit boardand heat generating components on the circuit board, and thus may notgive a reliable reading, or more particularly a reliable reading ofambient temperature outside the HVAC controller 18. Whereas atemperature sensor 102 connected to an extended cable 201 may be spacedfrom the circuit board 60 and heat generating components on the circuitboard 60, and may be positioned adjacent an outer wall of the housing200 of the HVAC controller and/or adjacent a vent 10 in the outer wall(FIG. 1).

External temperature sensor measuring circuit 70 may contain capacitivelow pass filter which may filtrate interference at higher frequencies.Usage of extended cable 201 may connect to sensor 102. When utilizedwith a floor heating system, shorter cables are harder to utilize. Ifthe extended cable 201 is utilized with an outdoor/external sensor, theoutdoor sensor can be put anywhere as distance would be not an issue.The present system and approach may avoid shorter (up to 5 meters)shielded cable lines.

A printed circuit board (PCB) thermal model may incorporate dissipatedpower from other electronic components such as a TRIAC, thermalresistance of power traces, a position of a compensation sensor, andambient sensor thermal cooling and position.

In some cases, the cable 201 may extend from, for example, the display86 or other component of the HVAC controller 18 along the interiorsurface of the housing 200, and connect to a connector on the printedcircuit board. In some cases, the interior surface of the housing 200may have features that interact with the cable to help position thetemperature sensor at a desired location within the housing 200, and togive the cable 201 additional support. The temperature sensor 102 may bemounted on the cable 201 and connected to the printed circuit board 60.The temperature sensor 102 may be facing and/or positioned adjacent alower part of the interior surface of the housing 200. When so provided,heat generated by electrical components within the housing 200 may tendto rise away from temperature sensor 102, thereby having less influenceon the sensed temperature.

In some cases, ambient air may be drawn in through the lower side of thehousing 200 through a vent or the like by thermal convection caused bythe heat generating components of the printed circuit board 60, and exitat the top side of the housing 200. The temperature sensor 102 may bepositioned near the lower side of the housing 200 and in the flow ofair, which may represent the ambient air temperature outside of thehousing 200.

For a given PCB 60 with metal traces or conductors carrying electricalpower and data, appropriate slots can be milled into the PCB 60 todepths corresponding to the thickness of the connectors (not shown). Theconnectors can then be snugly placed into those slots by hammering theminto the slots or with some other means of applying appropriatepressure. Glue may also be used to secure the connectors in those slotsif needed. The next step would be to solder the connectors to the metaltraces on the PCB for connecting them to power or signal lines on thePCB.

In some cases, external temperature sensor measuring circuit 70 may beprovided on PCB 60 to assist in protecting against electromagneticinterference (EMI), signal noise, and/or Electro-static discharge (ESD).The PCB 60 may be a multiple layer printed circuit board that includes alayer that is substantially a metal layer (e.g., a ground layer). Themetal layer may span across a proton of the PCB 60 and may provide ashied around sensor unit. The PCB 60 may include one or more filtercomponents, where the one or more filter components may be electricallycouples to at least one of the one or more terminals of the PCB 60. Thefilter components may include, for examples, one or more inductors,capacitors, filter capacitors, ESD diodes and/or any other componentssuitable for preventing or mitigating incoming and outgoing noise. Suchfilter components may be utilized to filter poor signals (e.g., powerand ground), output signals, and/or any other signals. The first side ofthe PCB may support a ground terminal, a power terminal, and one or moresensor output terminals on or near a sensor 102.

FIG. 7B, shows the present approach having readings with pseudo randomjittering. Modifying 300 Hz (or other frequency) reading principleJittering may be noted. In another version, the techniques herein allowfor reading operations to be adjusted based on external temperaturesensor 12 data available to a device regarding one or more individualtemperature readings. The correlation between the sensor data and theindividual reading of temperature may be modeled. In a further aspect,one or more parameters may be adjusted based on the conditions providedby the model. In yet another aspect, a supervisory device may receivesensor data from one or more other devices and initiate a networkoperation change by providing instructions to the one or more otherdevices based on the sensor data. The techniques described herein may beperformed by hardware, software, and/or firmware, which may includecomputer executable instructions executed by the processor 96 (FIG. 2).

Sensor data may include any readings regarding the physical conditionsexternal to network. For example, sensor data may be generated orderived from readings taken by a temperature sensor, a sound sensor, abarometer, a humidity sensor, or the like.

Referring now to FIG. 7A, a 300 Hz Principle is shown. This principleshown is generally known of rejecting 50 Hz or 60 Hz noises. Eachreading consists of 30 samples captured during 96.7 ms. The averagevalue of the captured samples is theoretically equal to zero. B1 sinewave denotes 50 Hz at 3 kS/s. B2 sine wave denotes 60 Hz at 3 kS/s. B3is the sample of one 50 Hz at 300 S/s. B4 is a sample of one 60 Hz at300 S/s. As shown, 6 samples are at one 50 Hz period and 5 samples atone 60 Hz period.

A present approach may be a way to lengthen wires of a temperaturesensor which is connected to thermostat. A goal may be achieved by acombination of both hardware (HW) and software (SW) filtering. Bothfiltering approaches may be combined.

An HW filter may be a simple filtering circuit having a specificallydesigned band to cancel low frequency noise but still not limittemperature readings (e.g., sampling).

An SW filter may be a specifically modified filtering algorithm able toremove noise produced by 50/60 Hz power lines. Another part of SWfiltering may be pseudo random jittering. This part may ensure thatfiltering will be very robust even in case when noise close to samplingfrequency occurs. Random jittering may cancel a contribution from thatkind of noise and ensure very accurate results which are completelycleaned up from all unwanted noise influences.

A combination of all the above mentioned items may result in a use ofmuch longer sensor wires (and make an installation easier) than thoseused up to now. The present approach may have wires that exceed wellbeyond 5 m in an installation. Thus, the combination of the notedfiltering approaches may be a feature of the present system.

To recap, a hydronic floor heating system with floor warming elementscoupled to a floor, may incorporate a programmable thermostat controllerwith a display, a first sensor for generating a signal indicative of anexternal temperature, a second sensor for generating a signal indicativeof an ambient temperature, and a processor connected to said first andsecond temperature sensors. The display may include a program schedulewhich allows a user to select one option when setting a low floortemperature limit.

The first sensor may be connected to thermostat terminals and ameasuring circuit.

The measuring circuit may contain a capacitive low pass filter whichfiltrates interference at higher frequencies.

The selection may provide a Yes option to ignore low floor temperaturelimits during a set period and a No option to maintain the low floortemperature limit.

The programmable thermostat may include a program schedule for settingvacation mode by a single setpoint based on a control mode.

The first sensor may be wired to the programmable thermostat with (forexample) a 100 meter (more or less) cable in combination with a hardwarefiltration.

The programmable thermostat may include software that contains a 300 Hzsampling process that ensures a filtering of 50 Hz and 60 Hz. Thesampling rate may be more or less, for instance, between 100 and 1000Hz. The filtering may be more or less than 50 Hz and 60 Hz.

The programmable thermostat may include software that contains apseudo-random function which has a reading interval of one or moreseconds in a spread interval at random times.

The spread interval may be at least +/− 1/50 Hz.

The spread interval may be at least +/−20 ms.

A hydronic floor heating thermostat configured to control one or morecomponents of an HVAC system, the thermostat may incorporate acontroller, a plurality of temperature sensors, a display with buttonsfor selecting, and a controller configured to provide one or morecontrol signals wherein the controller is configured to assist a user insetting a temperature limit within the thermostat by providing adecisive selection within the display for the user to select or allowone temperature limit to be set, and in response perform an action.

The decisive selection may need a Yes or No from a user.

Only an “Away” setpoint may be maintained based on a control mode.

The plurality of temperature sensors may measure at least externaltemperature and ambient temperature.

The thermostat may be connected to an external sensor using an extendedcable of at least 5 m.

An approach of implementing pseudo-random jittering in a hydronicflooring system, the approach may incorporate receiving a plurality ofindividual readings from sensor data regarding an external temperature,and modifying a 300 Hz or more or less Hz reading principle to theplurality of individual readings.

An external temperature sensor measuring circuit may contain acapacitive low pass filter which filtrates interference at higherfrequencies.

The individual readings may be randomly phase swept.

A phase uttering range may have an amplitude of at least +/−20 ms.

The individual reading period may be 1/300 Hz, or more or less.

Having thus described several illustrative versions of the presentdisclosure, those of skill in the art will readily appreciate that yetother versions may be made and used within the scope of the claimshereto attached. Numerous advantages of the disclosure covered by thisdocument have been set forth in the foregoing description. It will beunderstood, however, that this disclosure is, in many respect, onlyillustrative. Changes may be made in details, particularly in matters ofshape, size, and arrangement of parts without exceeding the scope of thedisclosure. The disclosure's scope is, of course, defined in thelanguage in which the appended claims are expressed.

Any publication or patent document noted herein is hereby incorporatedby reference to the same extent as if each individual publication orpatent document was specifically and individually indicated to beincorporated by reference.

In the present specification, some of the matter may be of ahypothetical or prophetic nature although stated in another manner ortense.

Although the present system and/or approach has been described withrespect to at least one illustrative example, many variations andmodifications will become apparent to those skilled in the art uponreading the specification. It is therefore the intention that theappended claims be interpreted as broadly as possible in view of therelated art to include all such variations and modifications.

What is claimed is:
 1. A method of implementing pseudo-random jitteringin a hydronic flooring system, the method comprising: receiving, by ameasuring circuit, a plurality of individual temperature readings from atemperature sensor; and applying, by the measuring circuit, a 300 Hzreading principle to the plurality of individual temperature readings.2. The method of claim 1, wherein the individual temperature readingsare randomly phase swept.
 3. The method of claim 1, further comprisingapplying, by the measuring circuit, pseudo-random jittering to theplurality of individual temperature readings.
 4. The method of claim 3,wherein the pseudo-random jittering has a phase jittering range havingan amplitude of at least +/−20 ms.
 5. The method of claim 1, whereinreceiving the plurality of individual temperature readings includesreceiving each individual temperature reading of the plurality over arespective reading period, wherein the individual period is 1/300 Hz. 6.The method of claim 1, wherein receiving the plurality of individualtemperature readings includes receiving each individual temperaturereading of the plurality over a respective reading period, wherein thereading period is more or less than 1/300 Hz.
 7. The method of claim 1,further comprising filtering, by the measuring circuit and from theplurality of individual temperature readings, noise produced by 50 Hzand 60 Hz power lines.
 8. A method of implementing pseudo-randomjittering in a hydronic flooring system, the method comprising:receiving, by a measuring circuit, a plurality of individual temperaturereadings from a temperature sensor; and applying, by the measuringcircuit, a more or less than 300 Hz reading principle to the pluralityof individual temperature readings.
 9. The method of claim 8, furthercomprising applying, by the measuring circuit, pseudo-random jitteringto the plurality of individual temperature readings.
 10. The method ofclaim 8, wherein the individual temperature readings are randomly phaseswept.
 11. The method of claim 8, further comprising filtering, by themeasuring circuit and from the plurality of individual temperaturereadings, noise produced by 50 Hz and 60 Hz power lines
 12. A system forimplementing pseudo-random jittering in a hydronic flooring system, thesystem comprising: a sensor configured to sense an external temperature;and a measuring circuit configured to: receive a plurality of individualtemperature readings from the sensor; and apply a 300 Hz readingprinciple to the plurality of individual temperature readings.
 13. Thesystem of claim 12, wherein the measuring circuit comprises a capacitivelow pass filter.
 14. The system of claim 12, wherein the measuringcircuit is configured to filter, from the plurality of individualtemperature readings, noise produced by 50 Hz and 60 Hz power lines. 15.The system of claim 12, wherein the sensor is configured to randomlyphase sweep the individual temperature readings of the plurality. 16.The system of claim 12, wherein the sensor is configured to applypseudo-random jittering to the sensing of the external temperature. 17.The system of claim 16, wherein the pseudo-random jittering comprises aphase jittering range having an amplitude of at least +/−20 ms.
 18. Thesystem of claim 12, further comprising a thermostat comprising thesensor.
 19. The system of claim 12, wherein each individual temperaturereading of the plurality comprises a respective temperature reading overa respective reading period, wherein the reading period is more or lessthan 1/300 Hz.
 20. The system of claim 12, wherein each individualtemperature reading of the plurality comprises a respective temperaturereading over a respective reading period, wherein the reading period is1/300 Hz.